484 



PHYSIOLOGY 



motor cortex and in certain other parts of the brain this contains 

 large solitary cells, which in the motor area receive the name of the 

 cells oj Betz. 



(5) Most internal of all, lying next to the white matter, is the 



Fit;. 218. Schematic representation of the neuro-fibrillar apparatus of a 

 cortical pyramidal cell. (After CAJAL.) 



a, axon ; dh, dendrites. 



polymorphous layer or inner cell lamina, composed of many types of 

 cells, among which spindle-shaped cells predominate. Other cells are 

 also found resembling pyramidal cells of the more superficial layer, 

 but directed in the reverse direction, so that their axons take a course 

 towards the surface. These are the cells of Martinotti. We also find 

 Golgi cells with a freely branching axon, which terminates in the 

 adjacent grey matter. 



